Completion!
The outer gown is silk taffeta with a silk chiffon overlay. It closes with spiral-laced rings below a false front, secured with tiny brass pins. Lacing rings also secure the foresleeves inside the wide sleeves of the bodice. The sleeves are decorated with couched cotton cord and pearls.
Also part of the outfit: a hand-strung pearl and jet necklace, crucifix on very teensy chain, and girdle belt (which I neglected to photograph until the very end, sorry).